High-potential-alternating-current rectifier.



lC. H.' THORDARSON.

HIGH POTENTIAL ALTERNATING CURRENT REGTIFIKER.

APPLIUATION FILED DB0. 7, 1908. Y

950,124. Y Patented @18h22, mw.

UNITED STATES, PAgEivir OFFICE.

CHESTER H. "IHoImARsoN, or CHICAGO, ILLINOIS.

HIGH-POTENTIAL-ALTERNATIN@CUimmer RECTIFIER.

,Specification of Letters IEatenl-z.v Patented Feb. 22, 1910.

Application led December 7, 1908. Serial No. 466,212.

, marked thereon, which -form a vpart of this.

specification.Y l

This invention relates to va rectifying ap? paratus for rectifying high tension alternating currentsand the invention has for4 its object to provide an exceedingly simple, practical and eflic'ient mechanical apparatus' capable of safely and economically changing alternating currents of unusual high po# tent-ial to unidirectional current without loss of energyl due to sparking at periods of coniinutation and having a minimum deterioration of the relatively movable commutator elements. Mechanical rectifying apparatus for this purposeheretofore -devised lhave lbeen practically limited to the rectifying of comparatively low potentials because of the great tendency of sparking between the oppositely polarized members of the rectifying apparatus. Since the width of the air' gap across which a spark will jump depends on'- the diiference'of potential between the oppositely polarized members of the apparatus, it followsthat the higher the potential of the current -to be rectified, the greater should be `the air gaps between the oppositely polarized members of the rectifying apparatus.

The main or principal feature of my inf ventionis'embraced in a construction and arrangement' of the relativelyI rotative commutator' elements, to-wit, the collector plates orbars and the commutator members, and the conductors connected therewith, whereby said elements and the conductors of opposite polarity are separated b air gaps of a widthproportional to the d iiile'rence of potential between the oppositelypolarized members of the apparatus, in such manner that said width is limited only-by the practical peripheral'v velocity ofthe rotative member of the apparatus.

` impro've the practical uses to -which my alternating' current rectifier may be putis found in the production of vcon-,'-

Am on directional current to the`wor Y may be observed that, instead -of taking the '-110- tinuous high potential unidirectional' electric discharges for the purpose of precipitating solidl mediums suspended inl lair or other gaseous mediums as a part of a process for reclaiming such solids which may be of "value, or-for purifying air containingdele terious fumes. Other uses of the rectified high potential direct currents -,will suggest themselves tothose skilled in this and analogous' arts.

A practical `rectifying apparatus which I have devised, and which is herein shown, consists of two -rotative arms lmade, of a ilight, substantial, 'non-conducting material,

fwhich are held rigidly separated at predelterji'iiined angles with respect to each other, 'and carry at their outer ends commutator vmembers which are adapted for Wi ing ,enf

g'agement with vangularly separated collector 'plates' disposed-on the circumference ofa 75y circle described by said conmiutator menibers, said arms and the commutator memberscarried thereby rotating in synchronism with the frequency of the alternating cur` rent being rectiied. The said `cenimutator members carried by the rotating arm mayl be connected with the source of`- alternating current to vbe rectified, while the collector' plates maybe connected withthe work circuit which'receivesthe rectiiedv'or unidi-l 85 rectional current. The said collector! plates are located at suoli distance apart on thec'ircumference of the circle described by thc commutator members 'that the said commu- -tator members make simultaneous contact 90 with collector-plates of opposite polarityl at the instant ofe'ective Value of the alternating current waves so that -a current of fulll value is transmitted in a 'given directionto the work circuit. In the further rotation of said arms the commutator members carried thereby are brought into cont-act with an-A 4other consecutive .pair of o positely polarized collector plates. The irection of How `ofthe alternating current in the said c'oin- 100' mutator members has, however, undergone a completechange so that current is delivered ,through said collector plates to the work circuit in the'saine direction as before. In'.

the continuous rotation of said arms, said Vcommutator members always deliver current of* the same signi-td the' same collector plates, thus transmitting aco' tinuous uni unidirectional current `from the collectorl circuit.Y It

plates, the operation' may be reversed, so-

that by'supplying alternatingy current to said collector plates, a rectified current may be obtained from the rotating commutator members. 1t may be furthermore observed that either of the sets of eommutator elements may be rotated while the other remains stationary relatively thereto, with the same results so far as is concerned the rectitication of the current. As the speed of the rotating member is directly proportional to the frequency of the current to be rectified, it follows that the lower the frequency of the current to.be rectified the greater can be made -the length of the arms carrying the commutator members without exceeding the limit of practical peripheral speed of said.

members and the corresponding increase in the air gap between the oppositely polarized points will permit the rectifying of -a correspondingly higher pressure current. Moreover, the apparatus is capable of an inverse operation in a manner to supply from the.

machine an alternating current that is derived from a source supplying a direct cur-f rent, the arrangement for eifecting such reversal being obvious.

Various means may be employed for operating the apparatus in synchronism with the alternating current frequency. For instance, a shaft carrying the rotative arms may constitute an extension of the shaft carrying the rotating member of an alternating current generator. lf, on the other hand, the current is to be rectied at a point distant from the generating station, the shaft carrying the rotating arms may be driven by means of a sychronous motor operated from the source of alternating current to be rectiied and connected direct to said shaft by-means of a sprocket chain, a gear or any other means designed to prevent mechanical slip between the motor and shaft.

In the following description and accompanying drawings is set forth one arrangement of the apparatus suitable for carrying out the invention but it is evident that the invention in its broader aspects is not confined to this particular gapparatus as the same results may be obtained by many arrangements of a similar-nature.

In the drawings t--Figure 1 'is a perspective view of an apparatus embodying my invention. Fig. 2 is a diagrammatic view illustrating electrical equipment and wiring.

In the said drawings, 10 designates a shaft rotatively mounted 1n a frame 11 made of wood or other insulatinff material, said frame providing support Ior either end of the shaft. Said vshaft is provided with twol collector rings 12 and 13 which are fastened to and rotate with the said shaft. Fixed to the shaft between said collector rings is a disk 1dr. made of somev light weight non-conducting material, as a strong liber. Formed on said dislr and extending at right angles to each other are two arms 'I 15 and 16 which carry at their outer ends current commutator members 1S and 19. rlhe currentl commutator member 18 is electrically connected to the collector ring 12 by means of a conductor`20 and a similar conductor 21 electrically connects the current commutator member 19 with the collector ring 13. In order to prevent vibration of said arms 15 and 1G, such as might tend to shift vthe commutator members 18 and 19 out of the planes of the arms during the rotation of the shaft, two braces 22 and 23,. of some strong, light, non-conducting material are provided, each attached at one end to one of said arms near its outer end and extending diagonally downwardly in a direction away from the conductor attached to said arm and fastened to the shaft. Alternating current is supplied to the commutator members 18 and 19 on the revolving arms 15 and 16 thiough the medium of Itwo brushes 2e and 25 Asuitably supported on the frame adjacent to and in wiping engagement with the collector rings 12 and 13. Said brushes are electrically connected to the secondary 26 of a high tension transformer 27, the vprimary 26l1 of which is supplied with current from an alternating current dynamo 28.

An auxiliary frame 29 mounted upon the frame 10 carries four-collector plates 30, 31, 32 and 33 of a suitable conducting material, said plates being disposed at four equidistant points on the circumference of the circle described by the conducting members 18 and 19 and concentric with respect to the shaft 11. Said collector plates are located in such position with respectmolthe plane of rotation of the arms' 15 and 16 Jthat the commutator members carried by said arms have wiping engagement withthe collector plates during the rotation oi' the shaft 1l. Two of said collector plates 31 and 351, located diametrically opposite to each other are connected by branch conductors 34 with one side 35 ot' the work circuit and the other oppositely located collector plates 31 and 32 are connected by branch conductors ldwith the other side 37 of the worlr circuit. The two sides of the work circuit may be connected with any desired high potential direct currentfapparatus and, as herein shown, are connected with two terminals 38 and 39 which may be the terminals of a high potential discharger.

l`he shaft 11 carrying the revolving commutator members is shown as rotated at a velocity in synehronism with the frequency of the current to be rectified by means of a synchronous motor 40 which is connected with and receives current from the same source .which supplies the` current to be rectified. The shaft of said motor is geared to the shaft 11 by means of aV sprocket chain the shaft :11 and the motor shaft.

I.t1-Which prevents mechanicalv slip between The operation of .he apparatus described f isas follows: 'By means of the synchronous motor 40, the shaft '11., vcarrying the revolvingcommutator members, -is rotated at a' velocity in synchronism with the frequency of the alternating current supplied from. the dynamo 28 and said'commutator members are brought ,-intowipingl engagement successivelyl with the collector plates. The said' commutator members arethusbrought into. simultaneous contactwith a` pair of adjacent' collector plates of opposite' polarityfand such contact occursv during the effective value in each commutator memberof an .alternating current wave of a g'en sign. fAt this instant` av positive4 current is transmitted.

.'througli one ofthe commutator members undone of the collector plates to the work. circuit, the other engaged collector plate I `lfieingin contactwith the-negative side'of the alternating 'current circuit. In the further angular displacement of the commutator meml'ie'rs they are brought into engagement with another pair of adj acentcollector plates of opposite polarity, oneof which was a plate of the former pair. In the meantime the alternating current `has undergone a complete changeI of, direction sothat the commutator member which'before delivered positive current now delivers vnegative cur rent. From the foregoinof l entthat the direction' of the alternating curit will be apparrenf is reversed during each quarter revolul'tio'irof the commutator members and that -the. diametrically opposite plates always collect currents ofthe same polarity so as to delivera continuous unidlrectlonal currentA -to the exterior or work circuit.

It isapparent that the construction de`- lscribed provides means for insulating'jthe 'commutator elements and the conductors connected therewithv by air gaps of suchy width as to permit the vrectification of altervhating currents of extremely high potential,

the widthy of the air gaps affording such* insulation being only limited by the .practi- -cal maximum velocity ofthe rotative members of thev apparatus. That'. is to say, the

'angular separation of commutator elements of opposite polarity results in an increasing diameter of the rotative member of the alpparatus and the construction described per-' `mits of any desired diameter of'such rotative part and corresponding widening' ofthe air gaps between commutator elements of 'opposite polarities up'to the'limit of peripheral speed of said rotative member of'the apparatus.

I claim as my invention V 1. A high potential alternating current rectifying apparatus comprising a plurale ity of rotative angularly separated, elongated, relatively light, thin arms made of .plates arranged on'the circumference of a non-conducting material .and provided 'with' y means for bracing them from flexurecut of the plane of rotation thereof and revolving at a speed 1n synchronism with the frequency of the alternating current to be rectified,

commutator members located at the outer4 ends of said .arms and connected with a -source supplying alternating current, and a plura-lityof angularly separated collector circley described by said commutator members and with which the-said commutator members are adapted for wipingl contact,

said ycollector plates collecting from 4the com- ',mutator members opposite polarities 'of a unidirectional current.'

2. An alternating current rectifying apparatus comprising a rotative' shaft, a plurality of light, angularly vseparated' arms madeof non-conducting material fixed raso y dially to and revolving with said shaft, commutator members carried by the outer ends of said arms and connected-with a source supplying alternating current, means for 'preventing flexure of said arms out of their plane of rotation, and a plurality of collector plates with which saidv commutator members have wiping contact,` consecutive ones, of which collect opposite polarities of a unidirectional current from said commutator members.

3.An alternating current rectifying apparatus. comprising a rotative shaft, two

.elongated angularly separated arms fixed 4radially to the shaft and made of a non-conducting material', said arms carrying .at their outer ends commutator members, col@ lector rings fixed to the shaft at either side of said arms, said collector rings vbeing in electrical commutation with brushes connected to a source supplying alternating current, conductors electrically connecting the said' collector rings with the commutator members,` and arranged to brace said arms' 4from flexure, each 11i-one direction', braces connected with said arms and said shaft for bracing' the arms, .each from fleXure in the opposite direction, and a plurality of col- -lector plates arranged on the circumference of a' circle described by thel commutator commutator members' have wiping contact lio and arranged to collect a unidirectional current therefrom, and means for revolving said commutator members at a speed in synchronism with the frequency of the current:

ported on said frame and arranged in the circumference ot' a circle described by the conductor members carried by said arms and with which said conductors have wiping contact, collector rings carredby sa'id shaft and electrically connected with the conductor members on said arms and means for bracing the arms to hold them in the plane of rota-l tion thereof.

In testimony, that 'I claim the foregoing as my invention l athx my signature in the presence of two Witnesses, this 30th day of Sept. A. D. 1908.

CHESTER H. THORDARSON.

Witnesses:

-WILLIAM L. HALL,

GEORGE lt. VVILKINS. 

